Current File : //lib/node_modules/npm/node_modules/verror/lib/verror.js
/*
* verror.js: richer JavaScript errors
*/
var mod_assertplus = require('assert-plus');
var mod_util = require('util');
var mod_extsprintf = require('extsprintf');
var mod_isError = require('core-util-is').isError;
var sprintf = mod_extsprintf.sprintf;
/*
* Public interface
*/
/* So you can 'var VError = require('verror')' */
module.exports = VError;
/* For compatibility */
VError.VError = VError;
/* Other exported classes */
VError.SError = SError;
VError.WError = WError;
VError.MultiError = MultiError;
/*
* Common function used to parse constructor arguments for VError, WError, and
* SError. Named arguments to this function:
*
* strict force strict interpretation of sprintf arguments, even
* if the options in "argv" don't say so
*
* argv error's constructor arguments, which are to be
* interpreted as described in README.md. For quick
* reference, "argv" has one of the following forms:
*
* [ sprintf_args... ] (argv[0] is a string)
* [ cause, sprintf_args... ] (argv[0] is an Error)
* [ options, sprintf_args... ] (argv[0] is an object)
*
* This function normalizes these forms, producing an object with the following
* properties:
*
* options equivalent to "options" in third form. This will never
* be a direct reference to what the caller passed in
* (i.e., it may be a shallow copy), so it can be freely
* modified.
*
* shortmessage result of sprintf(sprintf_args), taking options.strict
* into account as described in README.md.
*/
function parseConstructorArguments(args)
{
var argv, options, sprintf_args, shortmessage, k;
mod_assertplus.object(args, 'args');
mod_assertplus.bool(args.strict, 'args.strict');
mod_assertplus.array(args.argv, 'args.argv');
argv = args.argv;
/*
* First, figure out which form of invocation we've been given.
*/
if (argv.length === 0) {
options = {};
sprintf_args = [];
} else if (mod_isError(argv[0])) {
options = { 'cause': argv[0] };
sprintf_args = argv.slice(1);
} else if (typeof (argv[0]) === 'object') {
options = {};
for (k in argv[0]) {
options[k] = argv[0][k];
}
sprintf_args = argv.slice(1);
} else {
mod_assertplus.string(argv[0],
'first argument to VError, SError, or WError ' +
'constructor must be a string, object, or Error');
options = {};
sprintf_args = argv;
}
/*
* Now construct the error's message.
*
* extsprintf (which we invoke here with our caller's arguments in order
* to construct this Error's message) is strict in its interpretation of
* values to be processed by the "%s" specifier. The value passed to
* extsprintf must actually be a string or something convertible to a
* String using .toString(). Passing other values (notably "null" and
* "undefined") is considered a programmer error. The assumption is
* that if you actually want to print the string "null" or "undefined",
* then that's easy to do that when you're calling extsprintf; on the
* other hand, if you did NOT want that (i.e., there's actually a bug
* where the program assumes some variable is non-null and tries to
* print it, which might happen when constructing a packet or file in
* some specific format), then it's better to stop immediately than
* produce bogus output.
*
* However, sometimes the bug is only in the code calling VError, and a
* programmer might prefer to have the error message contain "null" or
* "undefined" rather than have the bug in the error path crash the
* program (making the first bug harder to identify). For that reason,
* by default VError converts "null" or "undefined" arguments to their
* string representations and passes those to extsprintf. Programmers
* desiring the strict behavior can use the SError class or pass the
* "strict" option to the VError constructor.
*/
mod_assertplus.object(options);
if (!options.strict && !args.strict) {
sprintf_args = sprintf_args.map(function (a) {
return (a === null ? 'null' :
a === undefined ? 'undefined' : a);
});
}
if (sprintf_args.length === 0) {
shortmessage = '';
} else {
shortmessage = sprintf.apply(null, sprintf_args);
}
return ({
'options': options,
'shortmessage': shortmessage
});
}
/*
* See README.md for reference documentation.
*/
function VError()
{
var args, obj, parsed, cause, ctor, message, k;
args = Array.prototype.slice.call(arguments, 0);
/*
* This is a regrettable pattern, but JavaScript's built-in Error class
* is defined to work this way, so we allow the constructor to be called
* without "new".
*/
if (!(this instanceof VError)) {
obj = Object.create(VError.prototype);
VError.apply(obj, arguments);
return (obj);
}
/*
* For convenience and backwards compatibility, we support several
* different calling forms. Normalize them here.
*/
parsed = parseConstructorArguments({
'argv': args,
'strict': false
});
/*
* If we've been given a name, apply it now.
*/
if (parsed.options.name) {
mod_assertplus.string(parsed.options.name,
'error\'s "name" must be a string');
this.name = parsed.options.name;
}
/*
* For debugging, we keep track of the original short message (attached
* this Error particularly) separately from the complete message (which
* includes the messages of our cause chain).
*/
this.jse_shortmsg = parsed.shortmessage;
message = parsed.shortmessage;
/*
* If we've been given a cause, record a reference to it and update our
* message appropriately.
*/
cause = parsed.options.cause;
if (cause) {
mod_assertplus.ok(mod_isError(cause), 'cause is not an Error');
this.jse_cause = cause;
if (!parsed.options.skipCauseMessage) {
message += ': ' + cause.message;
}
}
/*
* If we've been given an object with properties, shallow-copy that
* here. We don't want to use a deep copy in case there are non-plain
* objects here, but we don't want to use the original object in case
* the caller modifies it later.
*/
this.jse_info = {};
if (parsed.options.info) {
for (k in parsed.options.info) {
this.jse_info[k] = parsed.options.info[k];
}
}
this.message = message;
Error.call(this, message);
if (Error.captureStackTrace) {
ctor = parsed.options.constructorOpt || this.constructor;
Error.captureStackTrace(this, ctor);
}
return (this);
}
mod_util.inherits(VError, Error);
VError.prototype.name = 'VError';
VError.prototype.toString = function ve_toString()
{
var str = (this.hasOwnProperty('name') && this.name ||
this.constructor.name || this.constructor.prototype.name);
if (this.message)
str += ': ' + this.message;
return (str);
};
/*
* This method is provided for compatibility. New callers should use
* VError.cause() instead. That method also uses the saner `null` return value
* when there is no cause.
*/
VError.prototype.cause = function ve_cause()
{
var cause = VError.cause(this);
return (cause === null ? undefined : cause);
};
/*
* Static methods
*
* These class-level methods are provided so that callers can use them on
* instances of Errors that are not VErrors. New interfaces should be provided
* only using static methods to eliminate the class of programming mistake where
* people fail to check whether the Error object has the corresponding methods.
*/
VError.cause = function (err)
{
mod_assertplus.ok(mod_isError(err), 'err must be an Error');
return (mod_isError(err.jse_cause) ? err.jse_cause : null);
};
VError.info = function (err)
{
var rv, cause, k;
mod_assertplus.ok(mod_isError(err), 'err must be an Error');
cause = VError.cause(err);
if (cause !== null) {
rv = VError.info(cause);
} else {
rv = {};
}
if (typeof (err.jse_info) == 'object' && err.jse_info !== null) {
for (k in err.jse_info) {
rv[k] = err.jse_info[k];
}
}
return (rv);
};
VError.findCauseByName = function (err, name)
{
var cause;
mod_assertplus.ok(mod_isError(err), 'err must be an Error');
mod_assertplus.string(name, 'name');
mod_assertplus.ok(name.length > 0, 'name cannot be empty');
for (cause = err; cause !== null; cause = VError.cause(cause)) {
mod_assertplus.ok(mod_isError(cause));
if (cause.name == name) {
return (cause);
}
}
return (null);
};
VError.hasCauseWithName = function (err, name)
{
return (VError.findCauseByName(err, name) !== null);
};
VError.fullStack = function (err)
{
mod_assertplus.ok(mod_isError(err), 'err must be an Error');
var cause = VError.cause(err);
if (cause) {
return (err.stack + '\ncaused by: ' + VError.fullStack(cause));
}
return (err.stack);
};
VError.errorFromList = function (errors)
{
mod_assertplus.arrayOfObject(errors, 'errors');
if (errors.length === 0) {
return (null);
}
errors.forEach(function (e) {
mod_assertplus.ok(mod_isError(e));
});
if (errors.length == 1) {
return (errors[0]);
}
return (new MultiError(errors));
};
VError.errorForEach = function (err, func)
{
mod_assertplus.ok(mod_isError(err), 'err must be an Error');
mod_assertplus.func(func, 'func');
if (err instanceof MultiError) {
err.errors().forEach(function iterError(e) { func(e); });
} else {
func(err);
}
};
/*
* SError is like VError, but stricter about types. You cannot pass "null" or
* "undefined" as string arguments to the formatter.
*/
function SError()
{
var args, obj, parsed, options;
args = Array.prototype.slice.call(arguments, 0);
if (!(this instanceof SError)) {
obj = Object.create(SError.prototype);
SError.apply(obj, arguments);
return (obj);
}
parsed = parseConstructorArguments({
'argv': args,
'strict': true
});
options = parsed.options;
VError.call(this, options, '%s', parsed.shortmessage);
return (this);
}
/*
* We don't bother setting SError.prototype.name because once constructed,
* SErrors are just like VErrors.
*/
mod_util.inherits(SError, VError);
/*
* Represents a collection of errors for the purpose of consumers that generally
* only deal with one error. Callers can extract the individual errors
* contained in this object, but may also just treat it as a normal single
* error, in which case a summary message will be printed.
*/
function MultiError(errors)
{
mod_assertplus.array(errors, 'list of errors');
mod_assertplus.ok(errors.length > 0, 'must be at least one error');
this.ase_errors = errors;
VError.call(this, {
'cause': errors[0]
}, 'first of %d error%s', errors.length, errors.length == 1 ? '' : 's');
}
mod_util.inherits(MultiError, VError);
MultiError.prototype.name = 'MultiError';
MultiError.prototype.errors = function me_errors()
{
return (this.ase_errors.slice(0));
};
/*
* See README.md for reference details.
*/
function WError()
{
var args, obj, parsed, options;
args = Array.prototype.slice.call(arguments, 0);
if (!(this instanceof WError)) {
obj = Object.create(WError.prototype);
WError.apply(obj, args);
return (obj);
}
parsed = parseConstructorArguments({
'argv': args,
'strict': false
});
options = parsed.options;
options['skipCauseMessage'] = true;
VError.call(this, options, '%s', parsed.shortmessage);
return (this);
}
mod_util.inherits(WError, VError);
WError.prototype.name = 'WError';
WError.prototype.toString = function we_toString()
{
var str = (this.hasOwnProperty('name') && this.name ||
this.constructor.name || this.constructor.prototype.name);
if (this.message)
str += ': ' + this.message;
if (this.jse_cause && this.jse_cause.message)
str += '; caused by ' + this.jse_cause.toString();
return (str);
};
/*
* For purely historical reasons, WError's cause() function allows you to set
* the cause.
*/
WError.prototype.cause = function we_cause(c)
{
if (mod_isError(c))
this.jse_cause = c;
return (this.jse_cause);
};
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